Tag: Ion Engine

Japanese engineers have devised a plan to combine parts from two partially-failed ion engines to resume the Hayabusa asteroid probe’s journey back to Earth.

In a press release Thursday, officials said they will use the neutralizer of Thruster A and the ion source of Thruster B to provide enough power to guide the 950-pound spacecraft home next June.

Hayabusa launched in 2003 with four ion engines. Thruster A was shut down due to instability shortly after launch, while Thruster B was turned off after high voltage in its neutralization system.

Thruster C was manually switched off after signs it might be damaged by high electrical currents, and Thruster D failed two weeks ago due to a voltage spike.

The Nov. 4 glitch left Hayabusa without a propulsion system and put its scheduled return to Earth in serious doubt. But the new plan gives Japanese officials new hope.

“While the operation still needs monitored carefully, the project team has concluded the spacecraft can maintain the current return cruise schedule back to the Earth around June of 2010, if the new engines configuration continues to work as planned,” the Japan Aerospace Exploration Agency said in a statement.

Hayabusa’s four experimental microwave discharge ion engines consume xenon gas and expel the ionized propellant at high speeds to produce thrust. Ion engines are more efficient than conventional chemical thrusters because they use less fuel and can operate continuously for thousands of hours.

The craft’s thrusters have accumulated almost 40,000 hours of burn time since the probe launched.

Plans call for the spacecraft to continue thrusting until March, when it will shut down the ion system and coast toward Earth for a parachuted landing in Australia.